GIGANTEA is a Negative Regulator of Abscisic Acid Transcriptional Responses and Sensitivity in Arabidopsis
Articolo
Data di Pubblicazione:
2022
Citazione:
GIGANTEA is a Negative Regulator of Abscisic Acid Transcriptional Responses and Sensitivity in Arabidopsis / B. Siemiatkowska, M. Chiara, B.G. Badiger, M. Riboni, F. D'Avila, D. Braga, M.A.A. Salem, D. Martignago, S. Colanero, M. Galbiati, P. Giavalisco, C. Tonelli, T.E. Juenger, L. Conti. - In: PLANT AND CELL PHYSIOLOGY. - ISSN 0032-0781. - (2022). [Epub ahead of print] [10.1093/pcp/pcac102]
Abstract:
Transcriptional reprogramming plays a key role in drought stress responses, preceding the onset of morphological and physiological acclimation. The best-characterised signal regulating gene expression in response to drought is the phytohormone abscisic acid (ABA). ABA-regulated gene expression, biosynthesis and signalling are highly organised in a diurnal cycle, so that ABA-regulated physiological traits occur at the appropriate time of the day. The mechanisms that underpin such diel oscillations in ABA signals are poorly characterised. Here we uncover GIGANTEA (GI) as a key gatekeeper of ABA-regulated transcriptional and physiological responses. Time-resolved gene expression profiling by RNA sequencing under different irrigation scenarios indicates that gi mutants produce an exaggerated ABA response, despite accumulating wild-type levels of ABA. Comparisons with ABA-deficient mutants confirm the role of GI in controlling ABA-regulated genes and the analysis of leaf temperature, a read-out for transpiration, supports a role for GI in the control of ABA-regulated physiological processes. Promoter regions of GI/ABA-regulated transcripts are directly targeted by different classes of transcription factors, especially PHYTOCHROME-INTERACTING FACTORs, and (ABRE)-BINDING FACTOR, together with GI itself. We propose a model whereby diel changes in GI control oscillations in ABA responses. Peak GI accumulation at midday contributes to establishing a phase of reduced ABA sensitivity and related physiological responses, by gating DNA binding or function of different classes of transcription factors that cooperate or compete with GI at target regions.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
Arabidopsis thaliana; Circadian rhythms; Drought stress; Transcription factors;
Elenco autori:
B. Siemiatkowska, M. Chiara, B.G. Badiger, M. Riboni, F. D'Avila, D. Braga, M.A.A. Salem, D. Martignago, S. Colanero, M. Galbiati, P. Giavalisco, C. Tonelli, T.E. Juenger, L. Conti
Link alla scheda completa:
Link al Full Text: